diff --git a/core/lib/Drupal/Core/Entity/EntityFormController.php b/core/lib/Drupal/Core/Entity/EntityFormController.php
index 276ac34..c3e149b 100644
--- a/core/lib/Drupal/Core/Entity/EntityFormController.php
+++ b/core/lib/Drupal/Core/Entity/EntityFormController.php
@@ -218,7 +218,7 @@ public function processForm($element, $form_state, $form) {
       if (!$this->getFormDisplay($form_state)->getComponent($extra_field)) {
         $element[$extra_field]['#access'] = FALSE;
       }
-      else {
+      elseif (!isset($element[$extra_field]['#weight'])) {
         $element[$extra_field]['#weight'] = $info['weight'];
       }
     }
diff --git a/core/modules/comment/lib/Drupal/comment/CommentFormController.php b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
index 3cef2ff..48fed21 100644
--- a/core/modules/comment/lib/Drupal/comment/CommentFormController.php
+++ b/core/modules/comment/lib/Drupal/comment/CommentFormController.php
@@ -46,9 +46,7 @@ public function form(array $form, array &$form_state) {
       $form += $form_state['comment_preview'];
     }
 
-    $form['author'] = array(
-      '#weight' => 10,
-    );
+    $form['author'] = array();
     // Display author information in a details element for comment moderators.
     if ($is_admin) {
       $form['author'] += array(